Production of acids



March 20,1928. 1,663,524

I E. E. REID ET AL PRODUCTION OF ACIDS Filed Feb. 14, 1925 Liwuid. we:

' Vapor outlet 2 3 Jim" znlel' Q-inn inlet Fig.3

5 Reid and 0.5. Burke By Me /r a/fomey;

Draw 01370217 6 Patented Mar. 20, 1928.

UNITED sra'rss PAT EBENEZER EMMET REID,

WILMINGTON, DELAWARE,

OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

, rnonuo'rron or some.

Application filed February 14,1925. Serial No. 9,089.

This invention relates to the production of acids by the oxidation of hydrocarbons such as occur inp arailin, mineral oils, kerosene, gasolene, and so forth. In the production of such acids the temperature should be kept substantially below-300 (1., and preferably notlvabove 200 tion, but,.at temperatures as low as these, ellicient oxidation and conversion into "acids is difficult to attain ;by ordinary methods. We have devised a procedure whereby proper temperatures can be used and yet rapid working and high yields can be attained, It is a the major object of the invention to provide a procedure having the desirable characteristics indicated. The invention comprises as a-major feature subjecting the hydrocarbon to an oxygen-containinggas (air) "comminuted and disseminated throughout the oil in such an extreme degree of subdivision as to approach molecular dispersion. By proceeding in this way the speed of the reaction at a given temperature is multiplied many times as compared to the speed when the reaction is carried out at the given temperature by ordinary methods. Thus, by the present method desirable temperatures need not be exceed T ed and yet the manufacturing speed is high,

giving practical efficiency. I

In practically carrying out the treatment in accordance'with the invention we. preferably effect the subdivision of the air and its dissemination through the oil by a suitable stirrer driven at such high speeds as to give air bubbles of substantially a size obtainable by introducing the air with a Witt type 2 is "a bottom view stirrer of 1 inches in diameter rotated at a speed of 2000-4000 B. P. M., meaning by a \Vitt' type stirrer a stirrer of the type exemplified by the stirrer described in Berichte der Dent. Chem. GesclL, vol. 26, page 1696. In the accompanying drawing We have shown, without restriction of the invention thereto, a type of stirrer or agitator wit which our invention may be advantageously practiced. In the drawing :-Figure 1 is a sectionalview; Figure of the disc or distributory of the agitator shown in Figure 1;,and Figure 3 is. a bottom view of a simpler form "of disc. Referring to the drawing, the agitator comprises a suitable vessel 1, for bolding the oil to be treated, the samebeing diametrical vertical (1., to avoid decomposi-- med-i at 2000 to -bon .oils,

velocity, through The temperature at ,at approximately 175 equipped with liquid inlet 2, vapor out-v let 3, draw off pipe 4, and air inlets 5, 5, all suitably valved as indicated. A driving shaft 6 is mounted for rotation in the vessel by the bearings 7 and 8 and this shaft carries the distributor or agitator proper, 9. The distributor 9 is in'the character of a V v 1,663,524 ENT, OFFICE-.-

.OF BALTIMORE, MARYLAND, AND CHARLES E. BURKE. OF ASSIGNORS TO E. I. DU PONT DE NEMOURS ,& COMPANY,

disc and, as shown in Figures l and'2, may

have radial corrugations l0-upon the lower face thereof, or, as shown at 9* in Figure 3, may have a plain lower face. The ends,

ure 1, upturned and brought close to the surface of the disc near the centrethereof. If

desired, bafiles 11', 11 in any convenient num;

ber may be provided upon the WZLIl'Of the vessel, to )revent swirling of .the liquid when the distri utor 9 is rotated. In operation, the rapidly rotating distributor centrifugally moves the liquid outward from the centre of the disc, giving thorough agitation, and at the same time, the air issuing from the pipes '5, 5, under pressure and close to'the centre of distribution of the-liquid, bubbles through the liquid, is entrained in the travelling liquid and is centrifugally dispersed through the liquid in a degree of subdivision approaching molecular; dispersionf will vary with" the size of the disc and the amount of liquid to be agitated. With a cor h rial No. 482,592, on oxidation of hydrocar- 1921, wherein the oil filed July 5,

the stirrer and ejected at high the body of the oil, entraining air in its passage and mingling the entrained air with the body of the oil.

is drawn into carried out will, of course, vary with the material beingoxidized. We prefer to operate 0. when making acids The advisable speed of the stirrer which the reaction is 7-5, 5, of the air pipes are, asshown in Fig I 3 inches in diameter and o'perat such a pressure, v

by the oxidation of parafiin, although we activity of the hydrocarbon being oxidized.

In further accordance with our invention, the acids as produced are preferably converted as quickly as possibleinto metallic salts, whereby they are rendered-more sta vble and excessive decomposition prevented. Thus, we incorporate in the reaction mass, and agitate with the hydrocarbon and air, a dilute solution of sodium hydroxide, sodium carbonate, or some other alkaline solution,

aria formed, converting them into metallic sa ts. When such alkaline aqueous solutions are used in combination with the hydrocarbon and a temperature above that of the boiling point of the aqueous'solution is used, it is, of course, necessary to use pressure in order to retain the aqueous solvent in, a liquid state. In most cases we, have found that only such pressures are necessary as will prevent the volatilization of the water or other volatile products which may be formed during the course of the reaction,-say 3 to 215 lbs. per sq. in. gauge with temperature between 100 and 200 C., but higher pressures may be used if desirable.

The process may be illustrated in greater detail by the following example: A convenient quantity of paraflin is placed in"a vessel the stirrerrotated at approximately 3000' R. P. M. and the temperature raised to and maintained at ap roximately 175 C., and the pressure maintained at about 150 lbs. per sq. 1n. gauge. During the course of the re- -action considerable heat is evolved, and" if that when carrying out the process as just above indicated, about 60% of the paraflin was oxidized,

all was oxidized tofatty acids.

that will react with the acids as soon as theyadapted to withstand pressures of 15'0200.

Thematerial is first heated ext-er-- external heat is used at all after the reac-, tion is well started only enough is used totemperature, and other factors, we may state and of this 60% substantially It is to be understood that where we rcfer in the claims to hydrocarbon oil the term is to be taken to include, paraflin, mineral oils, kerosene, gasolene, and the like.

We claim: Y

1. The method of producing acids by the oxidation of hydrocarbon oil which comprises stirring and distributing the oil at high speed and at a temperature substantially below 300 C. and meanwhile introducing oxygen-containing gas below the surfacq' of the oil and in close relation to the centre of'distribution of the oil to thereby effect high "dissemination of the *gas, and cause the travelling oil to entrain the gas, thereby efl'ecting intimate mixture of the oil and gas; the stirring being at a speed to produce bubbles of substantially the size obtainable by introducing the gas with a VVitttype stirrer of 1 inches diameter rotated at a speed of 2000 to 4000 R. P. M. i

2. The method of producing acids by the oxidation of hydrocarbon oil which comprises stirring and distributing the oil at high speed and at a temperature of substantially 175 0. and meanwhile introducing oxygen-containing gas below the surface of the oil and in close relation to the centre of distribution of the 'oil to thereby efl'ect high disseminationof the gas, and cause the travelling oil to entrain the gas, thereby efiecting intimate mixture'of' the oil and gas; the stirring being at a speed to produce bubbles of substantially the size obtainable by introducing the gas with a Witt-type stirrer of 1 inches diameter rotated at .a.

speed of 2000 to 4000 R. P. M.

3. The method of producing acids by the oxidation of hydrocarbon oil which comprises stirring and distributing a mixture, of the oil and a water solution of an alkali compound of a character to react with the acids as soon as they are formed, to produce salts, at high speed and at a temperature of substantially" 175 C. and under a pressure suflicient to substantially prevent vaporization of the water of said solution at said temperature, and meanwhile introducing ;oxygen-containing gas below the surface of the oil and in close relation to the centre of distribution of the oil to thereby efiect high dissemination of the gas, and cause the travelling oil to entrain the 'gas, thereby efi'ecting intimate mixture of the oil, the "solution. and the gas; the stirring being at a. speed to produce bubbles of substantially the size obtainable by introducing the gas with a Witt-type stirrer of 1 inches diameter r0.- tated'at a speed of'2000 to 4000 R. P. M;

tures EBENEZER EMM'ET REID. CHARLES E. BURKE.

In testimony whereot we afiix our signa- 

